Fuel oil composition



the pour point of the fuels.

United States Patent 3,252,772 FUEL OIL COMPOSITION Thomas J. Clough,Glenwood, and David W. Young, Homewood, IiL, assignors to SinclairResearch, Inc., Wilmington, Del., a corporation of Delaware N0 Drawing.Filed Nov. 15, 1962, Ser. No. 238,039 4 Claims. (Cl. 44-62) Thisinvention relates to a novel polymer having particular utility as a pourdepressor for mineral oil fuels.

It is known in the art to add pour depressors to hydrocarbon fuels topermit their flow at low temperatures. Many different types of materialsare known to depress the pour point of hydrocarbon fuels but most haveto be employed in disadvantageously large concentrations to provide thedesired results.

We have now found that the oil-compatible polymerization products ofbutadiene-l,3 and a mixture of normal alpha olefins of 16 to 18 carbonatoms when added in small amounts of mineral oil fuels substantiallyreduce Moreover, it has been found that polymerization of butadiene witha mixture of C to C alpha olefins provides a polymer having unexpectedlysuperior pour depressing properties than say does a polymer of butadieneand a normal C alpha olefin alone.

The proportions of butadiene and the G -C alpha olefin polymerized mayvary and generally will fall in the range of about 1 to butadiene,preferably about 2 to 15% butadiene, and 99 to 80%, preferably about 98to 85% of the mixed alpha olefins. The mixed normal alpha-olefin ormonoalkene component consists essentially of at least about C olefin andat least about 20% C olefin. Often these olefins are in furtheradmixture with normal alpha-olefins of 10 to 24 or 12 to 20, carbonatoms, and in such mixtures the non-C to C olefins may be up to about50% of the overall component, frequently not more than about or Thepolymerization prod-uct of the present invention can be prepared bypolymerizing the butadiene and alphaolefins at a temperature of about--l0 C. to 100 (3., preferably about 0 to C. in the presence of aFriedel- Crafts catalyst, such as aluminum chloride, aluminum bromide,titanium tetrachloride, boron tri-fiuoride etherate, etc. The preferredcatalysts are metal halides, especially aluminum chloride. It ispreferred that an inert diluent for the catalyst be also employed andwhen used will generally be present in an amount of about 0.5 to 5volumes of diluent per volume of the mixed alpha-olefin feed. Suitableinert diluents are, for instance, alkanes of 3 to 8 carbon atoms such'aspropane, butane, pentane, hexane, octane as well as lower alkyl halidesof say 1 to 4 carbon atoms such as methyl chloride, ethyl chloride,propyl chloride and other non-polymerizable lower alkanes and alkylhalides. The Friedel-Crafts catalyst will generally be present incatalyst solution in a concentration of about .5 to 5% by weight,preferably 2 to 5% and the total amount of the catalyst employed isgenerally about 0.1 to 15% by weight per 100 parts of the polymer feed.

After the polymerization has been effected, either by batch orcontinuous operation, the resulting polymer can be separated fromresidual catalyst as by washing with water, alcohol, dilute aqueouscaustic soda or other suitable hydrolyzing and washing methods. Thepolymerization product is a normally liquid, light-colored, viscous oilhaving a Staudinger molecular weight of about 1,000 to 20,000. Thekinematic viscosity of the polymer will usually be about 30 to 600,preferably 75 to 300 centistokes at 210 F.

ride, used in the polymerization.

3,252,772 Patented May 24, 1966 The mineral oil bases which are improvedin accordance with this invention are liquid petroleum hydrocarbon fueloils boiling primarily above the gasoline range and include, forinstance, diesel fuels, domestic fuel oils, etc. These oils are usuallypetroleum middle distillates and commonly have relatively high pourpoints, for instance at least about l0 F. or higher. The oils can be intheir relativelycrude state or they can be treated in accordance withwell-known commercial methods such as acid or caustic treatment, etc.Fuel oils which can be improved by the polymers of this invention, are,for instance, hydrocarbon fractions boiling primarily in the range ofabout 300 to 750 F. The fuel oils can be straight run distillate fueloils, catalytically or thermally cracked distillate fuel oils ormixtures of straight run fuel oils, naphthas and the like with crackeddistillate stocks. The cracked materials will frequently be about 15 tovolume percent of the fuel.

The polymerization product of the present invention can be incorporatedin the mineral oil base by simply blending with stirring at ordinarytemperature or, if desired, a mixture of the oil and the polymerizationproduct can be heated to elevated temperatures, e.g. to C. withagitation. The polymerization product is added to the mineral oils insmall amounts suflicient to reduce the pour point. The actual amountsadded are dependent on the particular oil and polymerization prodnotemployed. Often the amounts will fall in the range of about .01 to 1% byweight or more preferably about 0.1 to 0.5%.

The following examples are included to further illustrate the presentinvention:

Example I To a mixture of alpha olefins of approximate composition:

7 Percent C alpha olefin 7 C 4 alpha olefin 16 C1 alpha olefin 40 Calpha olefin 30 C alpha olefin 7 was added 5% by weight butadiene-l,3. Areaction flask was equipped with 2 dropping funnels and a Dry Ice trapto remove and condense the volatile solvent, ethyl chlo- One droppingfunnel was charged with 128 ml. of the alpha olefin mixture containing5% l-3 butadiene. The remaining funnel was charged with 250 ml. of asaturated solution of AlCl in ethyl chloride at 5 C. Both the olefinmixture and catalyst solution were introduced into the 2-liter reactionflask at the same time, with the olefin mixture being introduced at arate of 25 ml./minute, the catalyst solution at 48 mL/minute. The totaltime for introducing olefin and catalyst solution was 5 minutes 20seconds, and the polymerization mixture was stirred for an additional 24minutes. 250 ml. of isopropyl alcohol was added to quench the catalyst,and 250 ml. of hexane was added. The polymer was washed with water andstripped Of solvents.

The polymer had a K.V. at 210 F. of 167.40 centistokes and an iodinenumber of 29.0.

Various amounts of polymer product were then blended with No. 2 fuel oiland the pour point of the blends determined. The No. 2 fuel is adistillate fuel oil composed of 50 volume percent water white distillatehaving an end point of 565 F. and 50 volume percent light cycle oilderived by catalytic cracking of gas oil. For comparison, the pour pointof No. 2 fuel oil without an additive was determined. The results areshown below:

Percent polymer: Pour point, F. 5

The data clearly demonstrate the pour point reducing properties of thepolymer of the present invention.

Example 11 I The same type of equipment was used as in Example I topolymerize a mixture of a C alpha-olefin and butadiene-1,3. One droppingfunnel was charged with 178 'ml. of the mixture of C alpha olefin and1-3 butadiene containing 13% by weight butadiene. The remaining droppingfunnel was charged with 270 ml. of a saturated solution of AlCl in ethylchloride at 12 C. Both olefin and catalyst solution were introduced intothe reaction flask at the same time, the olefin mixture being introducedat a rate of 35 mL/minute, the catalyst solution at a rate of 55rnL/minute. The total time for introducing olefin and catalyst was 5minutes, and the polymerization mixture was stirred for an additional 24minutes. 170 ml. of ethyl chloride was given off and trapped out of thesystem during the polymerization. The volatile ethyl chloride acted as acoolant to hold the temperature of polymerization constant. 250 m1. ofisopropyl alcohol was added to quench the catalyst, and 250 ml. ofhexane was added ,to dilute the polymer. The polymer was washed with theH and stripped of solvent material.

Percent polymer: Pour point F. 0.20 -35 0.10 10 Comparison of the dataof Example II with the data of Example I shows the unexpected pour pointreducing properties provided fuels by employing a polymer of a mixtureof C -C alpha olefins and butadiene as compared to a polymer andbutadiene of a normal C alpha olefin alone and butadiene.

It is claimed:

1. A composition consisting essentially of distillate liquid mineralfuel oil boiling primarily above the gasoline range containing a smallamount of a polymer consisting essentially of a normally liquid, mineraloil-compatible polymer of about 1 to 20% by weight butadiene and amixture of normal alpha olefins containing at least about 25% C normal,alpha olefin, at least about 20% C normal, alpha olefin and up to aboutof normal, alpha olefins in the C to C range other than C to C saidamount being sufficient to provide the fuel oil with a reduced pourpoint.

*2. The composition of claim 1 wherein the amount of butadiene is about2 to 15% by weight.

3. The composition of claim 2 wherein the amount of the polymer in themineral fuel oil is about .01 to 1% by weight.

4. The composition of claim 1 wherein the fuel oil boils primarily inthe range of about 300 to 750 F. and the polymer has a Staudingermolecular weight of about 1000 to 20,000.

References Cited by the Examiner UNITED STATES PATENTS 2,167,067 7/1939Gubelmann 260677 2,379,728 7/ 1945 Lieber.

2,551,641 5/1951 Seger .l 25259 X 2,746,925 5/1956 Garber 252592,982,628 5/ 1961 Lusebrink 44-62 2,984,550 5/1961 Chamot 4462 3,088,9855/1963 Wilke 260-677 DANIEL E. WYMAN, Primary Examiner.

C. O. THOMAS, J. E. DEMPS'EY,

Assistant Examiners.

1. A COMPOSITION CONSISTING ESSENTIALY OF DISTILLATE LIQUID MINERAL FUEL OIL BOILING PRIMARILY ABOVE THE GASOLINE RANGE CONTAINING A SMALL AMOUNT OF A POLYMER CONSISTING ESSENTIALLY OF A NORMALLY LIQUID, MINERAL OIL-COMPATIBLE POLYMER OF ABOUT 1 TO 20% BY WEIGHT BUTADIENE AND A MIXTURE OF NORMAL ALPHA OLEFINS CONTAINING AT LEAST ABOUT 25% C16 NORMAL, ALPHA OLEFIN, AT LEAST ABOUT 20% C18 NORMAL, ALPHA OLEFIN AND UP TO ABOUT 50% OF NORMAL, ALPHA OLEFINS IN THE C10 TO C24 RANGE OTHER THAN C16 TO C18, SAID AMOUNT BEING SUFFICIENT TO PROVIDE THE FUEL OIL WITH A REDUCED POUR POINT. 